He had driven his tractor down to the Maraetotara Stream on his Maraetuna farm, east of Havelock North, last week to remove the lid so the pump could be fixed.

He wrapped a chain around the lid, using the tractor to lift it off. He then jumped in the stream and reached under the lid to disconnect the wires when the chain slipped, dropping the lid and pinning his arm beneath it.

Unusually - and fortunately - he had his cellphone with him, as he was expecting the pump service company to ring him, despite the limited reception on the farm.

He used his free right arm to fish it out of his left pocket, but his emergency calls failed to connect.

But he found he could send texts, even if the damp screen made it hard to write anything legible.

With slippery fingers, he managed to send his friend Sandra Duthie the words "Help", "stuck", and "rivrr". "When I saw it had gone through, it gave me quite a relief," he said.

Duthie and friend Clint Wright responded immediately, making the 16-kilometre winding journey in just 20 minutes. "I knew he would never ask for help unless it was dire," Duthie said.

Along the way, they received another text that made them speed up: "Arm stuck need to loift ttactor will die".

Duthie said she was so relieved to see him still alive that she didn't think twice about sliding down the blackberry-strewn gully on her bottom.

"I could see his head above water, so I knew he wasn't dying on me."

Miller said he was pretty pleased to see the pair. Wright hopped on the tractor and lifted the concrete lid, freeing his arm, shortly before an ambulance, summoned by Duthie, arrived.

He was checked over at Hawke's Bay Hospital, but had suffered only a bit of bruising.

He enjoyed a nice glass of wine that night as he thought about how lucky he had been to have his cellphone on him.